On Sun, Jun 11, 2023 at 11:43:15PM +0300, Arseniy Krasnov wrote:
Hello Bobby! Thanks for this patchset! Small comment below:On 10.06.2023 03:58, Bobby Eshleman wrote:This commit drops the transport->dgram_dequeue callback and makes vsock_dgram_recvmsg() generic. It also adds additional transport callbacks for use by the generic vsock_dgram_recvmsg(), such as for parsing skbs for CID/port which vary in format per transport. Signed-off-by: Bobby Eshleman <bobby.eshle...@bytedance.com> --- drivers/vhost/vsock.c | 4 +- include/linux/virtio_vsock.h | 3 ++ include/net/af_vsock.h | 13 ++++++- net/vmw_vsock/af_vsock.c | 51 ++++++++++++++++++++++++- net/vmw_vsock/hyperv_transport.c | 17 +++++++-- net/vmw_vsock/virtio_transport.c | 4 +- net/vmw_vsock/virtio_transport_common.c | 18 +++++++++ net/vmw_vsock/vmci_transport.c | 68 +++++++++++++-------------------- net/vmw_vsock/vsock_loopback.c | 4 +- 9 files changed, 132 insertions(+), 50 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 6578db78f0ae..c8201c070b4b 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -410,9 +410,11 @@ static struct virtio_transport vhost_transport = { .cancel_pkt = vhost_transport_cancel_pkt, .dgram_enqueue = virtio_transport_dgram_enqueue, - .dgram_dequeue = virtio_transport_dgram_dequeue, .dgram_bind = virtio_transport_dgram_bind, .dgram_allow = virtio_transport_dgram_allow, + .dgram_get_cid = virtio_transport_dgram_get_cid, + .dgram_get_port = virtio_transport_dgram_get_port, + .dgram_get_length = virtio_transport_dgram_get_length, .stream_enqueue = virtio_transport_stream_enqueue, .stream_dequeue = virtio_transport_stream_dequeue, diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index c58453699ee9..23521a318cf0 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -219,6 +219,9 @@ bool virtio_transport_stream_allow(u32 cid, u32 port); int virtio_transport_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr); bool virtio_transport_dgram_allow(u32 cid, u32 port); +int virtio_transport_dgram_get_cid(struct sk_buff *skb, unsigned int *cid); +int virtio_transport_dgram_get_port(struct sk_buff *skb, unsigned int *port); +int virtio_transport_dgram_get_length(struct sk_buff *skb, size_t *len); int virtio_transport_connect(struct vsock_sock *vsk); diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h index 0e7504a42925..7bedb9ee7e3e 100644 --- a/include/net/af_vsock.h +++ b/include/net/af_vsock.h @@ -120,11 +120,20 @@ struct vsock_transport { /* DGRAM. */ int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *); - int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, - size_t len, int flags); int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *, struct msghdr *, size_t len); bool (*dgram_allow)(u32 cid, u32 port); + int (*dgram_get_cid)(struct sk_buff *skb, unsigned int *cid); + int (*dgram_get_port)(struct sk_buff *skb, unsigned int *port); + int (*dgram_get_length)(struct sk_buff *skb, size_t *length); + + /* The number of bytes into the buffer at which the payload starts, as + * first seen by the receiving socket layer. For example, if the + * transport presets the skb pointers using skb_pull(sizeof(header)) + * than this would be zero, otherwise it would be the size of the + * header. + */ + const size_t dgram_payload_offset; /* STREAM. */ /* TODO: stream_bind() */ diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index efb8a0937a13..ffb4dd8b6ea7 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1271,11 +1271,15 @@ static int vsock_dgram_connect(struct socket *sock, int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, int flags) { + const struct vsock_transport *transport; #ifdef CONFIG_BPF_SYSCALL const struct proto *prot; #endif struct vsock_sock *vsk; + struct sk_buff *skb; + size_t payload_len; struct sock *sk; + int err; sk = sock->sk; vsk = vsock_sk(sk); @@ -1286,7 +1290,52 @@ int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg, return prot->recvmsg(sk, msg, len, flags, NULL); #endif - return vsk->transport->dgram_dequeue(vsk, msg, len, flags); + if (flags & MSG_OOB || flags & MSG_ERRQUEUE) + return -EOPNOTSUPP; + + transport = vsk->transport; + + /* Retrieve the head sk_buff from the socket's receive queue. */ + err = 0; + skb = skb_recv_datagram(sk_vsock(vsk), flags, &err); + if (!skb) + return err; + + err = transport->dgram_get_length(skb, &payload_len);
What about ssize_t return value here? Or maybe a single callback that return both length and offset? .dgram_get_payload_info(skb, &payload_len, &payload_off)
+ if (err) + goto out; + + if (payload_len > len) { + payload_len = len; + msg->msg_flags |= MSG_TRUNC; + } + + /* Place the datagram payload in the user's iovec. */ + err = skb_copy_datagram_msg(skb, transport->dgram_payload_offset, msg, payload_len); + if (err) + goto out; + + if (msg->msg_name) { + /* Provide the address of the sender. */ + DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name); + unsigned int cid, port; + + err = transport->dgram_get_cid(skb, &cid); + if (err) + goto out; + + err = transport->dgram_get_port(skb, &port); + if (err) + goto out;Maybe we can merge 'dgram_get_cid' and 'dgram_get_port' to a single callback? Because I see that this is the only place where both are used (correct me if i'm wrong) and logically both operates with addresses: CID and port. E.g. something like that: dgram_get_cid_n_port().
What about .dgram_addr_init(struct sk_buff *skb, struct sockaddr_vm *addr) and the transport can set cid and port?
Moreover, I'm not sure, but is it good "tradeoff" here: remove transport specific callback for dgram receive where we already have 'msghdr' with both data buffer and buffer for 'sockaddr_vm' and instead of it add new several fields (callbacks) to transports like dgram_get_cid(), dgram_get_port()? I agree, that in each transport specific callback we will have same copying logic by calling 'skb_copy_datagram_msg()' and filling address by using 'vsock_addr_init()', but in this case we don't need to update transports too much. For example HyperV still unchanged as it does not support SOCK_DGRAM. For VMCI You just need to add 'vsock_addr_init()' logic to it's dgram dequeue callback. What do You think?
Honestly, I'd rather avoid duplicate code than reduce changes in transports that don't support dgram. One thing I do agree on though is minimizing the number of callbacks to call to reduce the number of indirection (more performance?). Thanks, Stefano
Thanks, Arseniy+ + vsock_addr_init(vm_addr, cid, port); + msg->msg_namelen = sizeof(*vm_addr); + } + err = payload_len; + +out: + skb_free_datagram(&vsk->sk, skb); + return err; } EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg); diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c index 7cb1a9d2cdb4..ff6e87e25fa0 100644 --- a/net/vmw_vsock/hyperv_transport.c +++ b/net/vmw_vsock/hyperv_transport.c @@ -556,8 +556,17 @@ static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr) return -EOPNOTSUPP; } -static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg, - size_t len, int flags) +static int hvs_dgram_get_cid(struct sk_buff *skb, unsigned int *cid) +{ + return -EOPNOTSUPP; +} + +static int hvs_dgram_get_port(struct sk_buff *skb, unsigned int *port) +{ + return -EOPNOTSUPP; +} + +static int hvs_dgram_get_length(struct sk_buff *skb, size_t *len) { return -EOPNOTSUPP; } @@ -833,7 +842,9 @@ static struct vsock_transport hvs_transport = { .shutdown = hvs_shutdown, .dgram_bind = hvs_dgram_bind, - .dgram_dequeue = hvs_dgram_dequeue, + .dgram_get_cid = hvs_dgram_get_cid, + .dgram_get_port = hvs_dgram_get_port, + .dgram_get_length = hvs_dgram_get_length, .dgram_enqueue = hvs_dgram_enqueue, .dgram_allow = hvs_dgram_allow, diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index e95df847176b..5763cdf13804 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -429,9 +429,11 @@ static struct virtio_transport virtio_transport = { .cancel_pkt = virtio_transport_cancel_pkt, .dgram_bind = virtio_transport_dgram_bind, - .dgram_dequeue = virtio_transport_dgram_dequeue, .dgram_enqueue = virtio_transport_dgram_enqueue, .dgram_allow = virtio_transport_dgram_allow, + .dgram_get_cid = virtio_transport_dgram_get_cid, + .dgram_get_port = virtio_transport_dgram_get_port, + .dgram_get_length = virtio_transport_dgram_get_length, .stream_dequeue = virtio_transport_stream_dequeue, .stream_enqueue = virtio_transport_stream_enqueue, diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index b769fc258931..e6903c719964 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -797,6 +797,24 @@ int virtio_transport_dgram_bind(struct vsock_sock *vsk, } EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind); +int virtio_transport_dgram_get_cid(struct sk_buff *skb, unsigned int *cid) +{ + return -EOPNOTSUPP; +} +EXPORT_SYMBOL_GPL(virtio_transport_dgram_get_cid); + +int virtio_transport_dgram_get_port(struct sk_buff *skb, unsigned int *port) +{ + return -EOPNOTSUPP; +} +EXPORT_SYMBOL_GPL(virtio_transport_dgram_get_port); + +int virtio_transport_dgram_get_length(struct sk_buff *skb, size_t *len) +{ + return -EOPNOTSUPP; +} +EXPORT_SYMBOL_GPL(virtio_transport_dgram_get_length); + bool virtio_transport_dgram_allow(u32 cid, u32 port) { return false; diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c index b370070194fa..bbc63826bf48 100644 --- a/net/vmw_vsock/vmci_transport.c +++ b/net/vmw_vsock/vmci_transport.c @@ -1731,57 +1731,40 @@ static int vmci_transport_dgram_enqueue( return err - sizeof(*dg); } -static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk, - struct msghdr *msg, size_t len, - int flags) +static int vmci_transport_dgram_get_cid(struct sk_buff *skb, unsigned int *cid) { - int err; struct vmci_datagram *dg; - size_t payload_len; - struct sk_buff *skb; - if (flags & MSG_OOB || flags & MSG_ERRQUEUE) - return -EOPNOTSUPP; + dg = (struct vmci_datagram *)skb->data; + if (!dg) + return -EINVAL; - /* Retrieve the head sk_buff from the socket's receive queue. */ - err = 0; - skb = skb_recv_datagram(&vsk->sk, flags, &err); - if (!skb) - return err; + *cid = dg->src.context; + return 0; +} + +static int vmci_transport_dgram_get_port(struct sk_buff *skb, unsigned int *port) +{ + struct vmci_datagram *dg; dg = (struct vmci_datagram *)skb->data; if (!dg) - /* err is 0, meaning we read zero bytes. */ - goto out; - - payload_len = dg->payload_size; - /* Ensure the sk_buff matches the payload size claimed in the packet. */ - if (payload_len != skb->len - sizeof(*dg)) { - err = -EINVAL; - goto out; - } + return -EINVAL; - if (payload_len > len) { - payload_len = len; - msg->msg_flags |= MSG_TRUNC; - } + *port = dg->src.resource; + return 0; +} - /* Place the datagram payload in the user's iovec. */ - err = skb_copy_datagram_msg(skb, sizeof(*dg), msg, payload_len); - if (err) - goto out; +static int vmci_transport_dgram_get_length(struct sk_buff *skb, size_t *len) +{ + struct vmci_datagram *dg; - if (msg->msg_name) { - /* Provide the address of the sender. */ - DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name); - vsock_addr_init(vm_addr, dg->src.context, dg->src.resource); - msg->msg_namelen = sizeof(*vm_addr); - } - err = payload_len; + dg = (struct vmci_datagram *)skb->data; + if (!dg) + return -EINVAL; -out: - skb_free_datagram(&vsk->sk, skb); - return err; + *len = dg->payload_size; + return 0; } static bool vmci_transport_dgram_allow(u32 cid, u32 port) @@ -2040,9 +2023,12 @@ static struct vsock_transport vmci_transport = { .release = vmci_transport_release, .connect = vmci_transport_connect, .dgram_bind = vmci_transport_dgram_bind, - .dgram_dequeue = vmci_transport_dgram_dequeue, .dgram_enqueue = vmci_transport_dgram_enqueue, .dgram_allow = vmci_transport_dgram_allow, + .dgram_get_cid = vmci_transport_dgram_get_cid, + .dgram_get_port = vmci_transport_dgram_get_port, + .dgram_get_length = vmci_transport_dgram_get_length, + .dgram_payload_offset = sizeof(struct vmci_datagram), .stream_dequeue = vmci_transport_stream_dequeue, .stream_enqueue = vmci_transport_stream_enqueue, .stream_has_data = vmci_transport_stream_has_data, diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c index 5c6360df1f31..2f3cabc79ee5 100644 --- a/net/vmw_vsock/vsock_loopback.c +++ b/net/vmw_vsock/vsock_loopback.c @@ -62,9 +62,11 @@ static struct virtio_transport loopback_transport = { .cancel_pkt = vsock_loopback_cancel_pkt, .dgram_bind = virtio_transport_dgram_bind, - .dgram_dequeue = virtio_transport_dgram_dequeue, .dgram_enqueue = virtio_transport_dgram_enqueue, .dgram_allow = virtio_transport_dgram_allow, + .dgram_get_cid = virtio_transport_dgram_get_cid, + .dgram_get_port = virtio_transport_dgram_get_port, + .dgram_get_length = virtio_transport_dgram_get_length, .stream_dequeue = virtio_transport_stream_dequeue, .stream_enqueue = virtio_transport_stream_enqueue,
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